Sadly, I sweat when I run...like most people. This product cannot be used when you sweat. (It says so in the directions.)
Also, I run fast BUT I can almost guarantee my heart rate never went to and stayed at the 900+ mark. I'm not sure if the fault was in the product design or I just got a faulty one but...I returned it for refund.Get more detail about Finger Heart Rate Monitor Stopwatch.
